The invention relates to an apparatus for operating a resolver, which has at least one receiver winding and at least one excitation winding, which are/can be associated with a rotatably mounted shaft, in particular a rotor shaft of an electric motor, said apparatus also having a device which determines an angular position of the shaft as a function of an induced voltage generated by the excitation winding by means of a desired excitation signal, which can in particular be predetermined by the device and has a predeterminable frequency and amplitude, and said induced voltage is detected by the receiver winding.
The invention furthermore relates to a method for operating such a resolver as well as a resolver device.
A resolver is frequently used to detect the angular position of a rotor of an electric motor even in the motor vehicle industry. The resolver constitutes an electromagnetic transducer, which transmits an electrical variable, in particular a voltage, as a function of the angular position of the rotor. To this end, the resolver generally has a housing in which two receiver windings are disposed which are offset to one another by 90% and which enclose the rotor rotatably mounted in the housing. At least one excitation winding is furthermore associated with the rotor, said excitation winding being operated with a predeterminable desired excitation signal, which has a predeterminable frequency and a predeterminable amplitude. The excitation winding as well as the receiver winding can be fixedly disposed in the housing, respectively on the stator side, wherein the excitation winding generates a magnetic field in the rotor or respectively in the shaft per induction, which in turn induces a voltage into the receiver winding. The coupling in the receiver winding is in this case dependent on the position of the shaft or respectively the rotor, so that the position of the rotor or respectively the shaft can be suggested by evaluating the signal induced into the receiver winding.
The resolver is typically connected to a corresponding evaluation device or a control device by means of a simple plug connection comprising a corresponding evaluation device or a control device. If the resolver is incorrectly wired in or connected so that the connections of the excitation winding are interchanged, this leads to the detected position information being inverted.